Three major domestic softwoods, Korean red pine, Korean pine and larch, were heat-treated at $220^{circ}C$ and for various treatment times for color changing. A new heat treatment equipment was developed for this study and was revealed working well for changing the colors of the three softwoods. The color difference index of 15 was obtained after 8 hours for Korean red pine and Korean pine, and 10 hours for Larch. The correlations of brightness, redness and yellowness with treatment time were different between species.